Continuous casting machine embodying a self-aligning and flexing guide-roll rack

ABSTRACT

A guide-roll rack for use in a continuous-casting machine. The rack is formed of a short-length upper section and a longer lower section which is made up of individual subsections. Both the upper and lower sections are supported on a frame which rests on the supporting structure of the machine. The rack is stationary vertically but can shift horizontally to a limited extent to facilitate aligning it with the mold and its sections and subsections with one another. The mold-support frame oscillates vertically, but carries rollers which ride against the upper section of the rack for aligning the rack with the mold. The sections and subsections are flexibly connected to assure proper alignment.

[ 51 Sept. 24, 1974 3,528,488 9/1970 Bode, 3,612,156 10/1971 Schoffmann.........

[ CONTINUOUS CASTING MACHINE EMBODYING A SELF-ALIGNING AND FLEXING GUIDE-ROLL RACK 3,631,916 9/1970 Schwartz..........

164/260 X Hoffmann et [75] Inventor: Charles H. Bode, Jr.,' Upper St.

Clair Twp, Allegheny County, Pa.

Assignee: United States Steel Corporation,

Primary Examiner-R. Spencer Annear Pittsburgh p Attorney, Agent, or Firm-Walter P. Wood Aug. 1, 1972 [22] Filed:

[57] ABSTRACT A guide-roll rack for use in a continuous-casting ma- 211 Appl. No.: 277,709

Related US. Application Data [62] Division of Ser. No. 143,077, May 13, 1971, Pat. No.

ary vertically but can shift horizontally to a limited extent to facilitate aligning it with the mold and its sec- 22. 0 l 41 i 6. 7% 1 3.,2/ Boo3 4 .l 6 mim 0 my m9 4 n 6 U mm mmh ".r .u a a 1" t 0 t a 5mm U F 1:11. 2 00 555 1.1.1

tions and subsections with one another. The mold- 11 t' 11 l References Cited support frame osci ates ver ica y, but carries ro lers UNITED STATES PATENTS which ride against the upper section of the rack for aligning the rack with the mold. The sections and sub- 1,385,595 7/1921 Van Ranst...........,.......... 2,130,202 9/1938 Tama..........

3,528,482 9/1970 Fastert........ 3,528,483 9/1970 Ma1lener.............................

PAIENIEMtmwu sum 5 or a v PAIENIEDSEPZMSM v v saw a or a FIG. 7

This is a division of application Ser. No. 143,077, filed May 13, 1971, which issued as US. Pat. No. 3,700,073, Oct. 24, 1972.

This invention relates to an improved guide-roll rack for use in a continuous-casting machine.

In a conventional continuous-casting operation, liquid metal is poured through an open-ended watercooled vertically oscillating mold. A casting, which at this stage has only a relatively thin solidified skin and a liquid core, emerges continuously from the lower end of the mold. Immediately beneath the mold the casting travels through a series of idler guide rolls, where water is sprayed on its surface to effect further solidification. The guide rolls define a pass which must be accurately aligned throughout its height to confine the casting and accurately aligned also with the mold and with power driven pinch rolls below. Any misalignment of the guide rolls can rupture the skin of the casting and cause a break-out of liquid metal. The severe conditions under which guide rolls operate necessitate that they be removed frequently for maintenance or replacement, particularly the rolls nearest the mold where the casting is at its greatest temperature. It is of course necessary to shut down the whole operation to change guide rolls.

To facilitate properly aligning guide rolls with one another and with a mold, it is known to mount the rolls in rack sections which are joined to adjacent sections with pivoted links. Reference can be made to Hess et al. US. Pat. No. 3,167,829 for a showing of a guide-roll rack of this construction. The known arrangement affords almost unlimited flexibility between the rack sections. My observation has been that such unlimited flexibility can itself cause damage to a casting, as it permits the casting to weave uncontrollably.

An object of my invention is to provide an improved guide-roll rack which is formed of flexibly related sections and subsections to permit limited weaving of the descending casting, but in which flexing is controlled and takes place only to the extent needed to align the rolls.

A further object is to provide an improved guide-roll rack which can be installed readily in a casting machine or removed for maintenance or replacement, and in which the rolls nearest the mold can be removed without disturbing the others.

A further object is to provide a combination of mold support and guide-roll rack which embody improved means for maintaining the uppermost vertically stationary rolls in proper alignment with a vertically oscillating mold thereabove.

In the drawings:

FIG. 1 is a side elevational view with parts broken away of a guide-roll rack constructed in accordance with my invention, along with a portion of the surrounding structure in a continuous-casting machine;-

FIG. 2 is a top plan view of the roll rack shown in FIG. 1;

FIG. 3 is a horizontal sectional view on a larger scale showing how I mount the guide rolls and edge rolls in the uppermost rack section;

FIG. 4 is a vertical section on a larger scale on line IVIV of FIG. 2 showing the hold-down embodied in my roll rack;

FIG. 5 is a vertical section on line V-V of FIG. 2;

FIG. 6 is a horizontal section on line VI-VI of FIG.

FIG. 7 is a diagrammatic side elevational view showing a modification; and

FIG. 8 is a diagrammatic side elevational view showing another modification.

FIG. 1 shows a fixed supporting structure 10 of a continuous-casting machine, which can be conventional apart from my novel guide-roll rack and my novel means for maintaining the uppermost section of the rack in alignment with the mold. The machine includes a mold-support frame 12, an open-ended water-cooled mold 13 carried by said frame, and a drive cam 14 (shown only diagrammatically) for vertically oscillating the frame and mold. The rack comprises a relatively short upper section 15 located immediately beneath mold 13 and a relatively long lower section 16 located beneath the short section. The long section is made up of individual subsections 16a, 16b and 160. The casting machine includes a conventional power driven pinchroll assembly 17 located immediately beneath the long section 16 of the roll rack.

Both sections 15 and 16 of the mold rack are removably supported on a non-oscillating rigid frame 21, which removably rests on the supporting structure 10. Frame 21 is rectangular in plan, as shown in FIG. 2. The supporting structure 10 has upstanding locating pins 22 received in corresponding oversize holes 23 in frame 21, whereby the frame can be dropped readily into its proper position, but can shift horizontally to a limited extent. The frame includes four horizontal shelves 24 located within its respective interior corners for supporting the short section 15, as hereinafter described. Each of the end members of the frame carries a pair of pivot pins 25 (four altogether). Respective semiflexible links 26 depend from pivot pins 25 for supporting the long section 16, as hereinafter described. The lower ends 27 of links 26 are tapered to fit within corresponding sockets in the pinch-roll assembly 17.

The short section 15 includes a pair of girders 29 at its opposite ends resting on shelves 24. The ends of the girders have depending dowels 30 received in oversize holes 31 in shelves 24 to locate the short section 15 properly, yet permit it to have limited horizontal movement with respect to frame 21. Preferably, l pivot holddown levers 32 of inverted U-shape to the respective shelves 24 (FIG. 4). The ends of the girders 29 have inwardly projecting tabs 33 which are received within the bights of said levers. The levers carry spring-pressed plungers 34 which have rounded tips at their lower ends received in oversize rounded depressions 35 in the upper faces of tabs 33 to allow limited horizontal shifting of the short section 15 with respect to frame 21. Thus the hold-down devices prevent the short section 15 from vibrating up and down, but readily can be pivoted clear of the tabs so as not to interfere with lifting the section from frame 21.

As best shown in FIGS. 2 and 3, girders 29 carry a cage 38 which is rectangular in plan and in which I journal a'series of vertically spaced opposed pairs of guide rolls 39 and 40 and edge rolls 4] and 42. Preferably the bearings for the guide rolls 39 at the left occupy a fixed position with respect to the frame, while the bearings for the guide rolls 40 at the right can be adjusted horizontally to vary the spacing between guide rolls. To permit such adjustment, the bearings for rolls 40 are mounted on a bracket 43 which has a slot 44 (FIG. 3). The guide rolls and edge rolls define a pass for confining a partially solidified casting coming from the mold.

The exterior side faces of the cage 38 carry four pads 45 (FIG. 2). The inner faces of girders 29 carry pads 46 outside cage 38. The mold-support frame 12 carries four depending brackets 47 (FIG. 1). The inner faces of the respective brackets carry bearings 48 in which I journal rollers 49 and 50 (FIG. 2). As the mold-support frame 12 oscillates vertically, the four rollers 49 and the four rollers 50 ride up and down along the respective pads 45 and 46 and thus maintain the nonoscillating short section of the roll rack in accurate alignment with the mold 13.

As best shown in FIGS. 1 and 6, the uppermost subsection 160 of the long section 16 includes a cage 51 which is rectangular in plan. The end walls of cage 51 carry exterior trusses 52 which I attach to the four links 26. In this embodiment the respective trusses 52 are attached to the respective links with upper and lower pivot pins 53 and 54. Within cage 51 I journal a series of vertically spaced opposed pairs of guide rolls 55 and 56 and edge rolls 57 and 58. Preferably the bearings for the guide rolls 55 at the left are fixed and the bearings for the guide rolls 56 at the right can be adjusted, similar to the bearings in the short section 15 thereabove. The other two subsections 16b and 160 are of similar construction to the uppermost subsection 16a;- hence I have not repeated the description.

As shown in FIG. 1, water inlet pipes 59 extend upwardly through the supporting structure 10. Frame 21 carries respective mating continuations 60 of pipes 59 leading to conventional spray nozzles (not shown) between the guide rolls. I interpose suitable seals between the ends of pipes 59 and 60.

FIG. 7 shows a modification in which the links 26 are attached to the trusses of the subsections 16a, 16b and 160 with pivot pins 61 located intermediate the height of the subsection. F IG. 8 shows another modification in which subsections 16a, 16b and 160 are attached to the frame 21 and to one another with individual shortlength links 62 and pivot pins 63 and 64 at top and bottom. The lowermost link 62a is tapered at its lower end, as indicated at 65, for engagement with the pinch roll assembly 17.

In operation, the pivotal connections of the links 26 or 62 to the frame 21, and the pivotal connections of the subsections 16a, 16b and 16c to these links, afford sufficient flexibility that the guide rolls 55 and 56 ofthe long section 16 align themselves automatically with the guide rolls 39 and 40 ofthe short section 15. As already explained, the rollers 49 and 50 automatically align the short section with the mold l3. Engagement of the tapered lower ends of the links 26 or 62a with the pinchroll assembly 17 assures that the guide-roll rack remains in alignment at its lower end with the pinch rolls. The individual links 62 of FIG. 8 of course afford the greatest degree of flexibility, forming in effect a parallelogram linkage, while the continuous links 26 of FIG. I afford the least. Nevertheless in all three embodiments the degree of flexing is limited, and the sections cannot flex to an extent that they distort the casting, yet they allow necessary weaving of the casting.

To disassemble the rack, the mold support frame 12 and mold 13 first are lifted out of the way. Thereafter the frame 21, together with both the short and long sections 15 and 16, can be lifted as a unit from the supporting structure 10. Alternatively the short section 15 can be lifted separately from the frame 21, leaving frame 21 and the long section 16 in place. The rolls of the short section require the most frequent attention, and can be removed without disturbing the others. The continuation of the water inlet pipes 59 are lifted out with the frame 21.

From the foregoing description it is seen that my invention affords a flexible mold discharge roll-rack which is self-aligning with an oscillating mold and within itself. At the same time flexing is limited to prevent damage to a casting. The rack is readily removed and disassembled for maintenance. To simplify the showing I have omitted the nozzles to which pipes 59 and 60 are connected, along with other conventional parts not directly involved in my invention.

I claim:

1. A continuous-casting machine comprising a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said mold-support frame, means carried by said structure for oscillating said mold-support frame and said mold vertically, a vertically stationary roll rack carried by said structure and extending downwardly from said mold, and a pinch roll assembly beneath said roll rack, said rack comprising:

a frame supported in a stationary vertical position on said supporting structure;

a relatively short upper section suported on said frame for limited horizontal movement;

a relatively long lower section beneath said upper section and being formed of a plurality of individual subsections; and

means suspending said lower section from said frame and allowing limited flexing of the lower section and the individual subsections thereof;

said upper section and said subsections each including a cage and rolls journaled in said cage defining an aligned pass for confining a partially solidified casting.

2. A continuous-casting machine as defined in claim 1 in which said rack is horizontally shiftable with respect to said structure, said machine further comprising cooperating means on said mold-support frame and the upper section of said rack for maintaining said upper section in alignment with said mold as said mold oscillates up and down and said upper section remains stationary.

3. A continuous-casting machine as defined in claim 2 in which said cooperating means includes bearings fixed to the underside of said mold support frame, rollers journaled in said bearings, and pads fixed to said upper section, said rollers riding on said pads.

4. A continuous-casting machine as defined in claim 1 in which both sections of said roll rack can be removed as a unit, or the upper section of said roll rack can be removed without disturbing said lower section.

5. In a continuous-casting machine which comprises a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said frame, means carried by said structure for oscillating said frame and said mold vertically, and a horizontally shiftable vertically stationary guide-roll rack carried by said structure beneath said mold, the combination therewith of a mechanism for maintaining said rack in alignment with said mold, said mechanism comprising a plurality of brackets depending from said frame at spaced apart locations, and rollers journaled to said brackets to oscillate up and down with the frame, said rollers riding against opposed faces of said rack.

6. A combination as defined in claim 5 in which said rack includes a cage rectangular in plan, and the faces against which said rollers ride lie at right angles to each other adjacent the respective corners of said cage.

7. In a continuous-casting machine which comprises a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said frame, means carried by said structure for oscillating said frame and said mold vertically, and a horizontally shiftable vertically stationary guide-roll rack carried by said structure beneath said mold, the combination therewith of cooperating means on said frame and said roll rack for maintaining said roll rack in alignment with said mold as said mold moves up and down while said roll rack is stationary;

gles to each other at the respective corners against which said rollers ride. 

1. A continuous-casting machine comprising a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said mold-support frame, means carried by said structure for oscillating said mold-support frame and said mold vertically, a vertically stationary roll rack carried by said structure and extending downwardly from said mold, and a pinch roll assembly beneath said roll rack, said rack comprising: a frame supported in a stationary vertical position on said supporting structure; a relatively short upper section suported on said frame for limited horizontal movement; a relatively long lower section beneath said upper section and being formed of a plurality of individual subsections; and means suspending said lower section from said frame and allowing limited flexing of the lower section and the individual subsections thereof; said upper section and said subsections each including a cage and rolls journaled in said cage defining an aligned pass for confining a partially solidified casting.
 2. A continuous-casting machine as defined in claim 1 in which said rack is horizontally shiftable with respect to said structure, said machine further comprising cooperating means on said mold-support frame and the upper section of said rack for maintaining said upper section in alignment with said mold as said mold oscillates up and down and said upper section remains stationary.
 3. A continuous-casting machine as defined in claim 2 in which said cooperating means includes bearings fixed to the underside of said mold support frame, rollers journaled in said bearings, and pads fixed to said upper section, said rollers riding on said pads.
 4. A continuous-casting machine as defined in claim 1 in which both sections of said roll rack can be removed as a unit, or the upper section of said roll rack can be removed without disturbing said lower section.
 5. In a continuous-casting machine which comprises a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said frame, means carried by said structure for oscillating said frame and said mold vertically, and a horizontally shiftable vertically stationary guide-roll rack carried by said structure beneath said mold, the combination therewith of a mechanism for maintaining said rack in alignment with said mold, said mechanism comprising a plurality of brackets depending from said frame at spaced apart locations, and rollers journaled to said brackets to oscillate up and down with the frame, said rollers riding against opposed faces of said rack.
 6. A combination as defined in claim 5 in which said rack includes a cage rectangular in plan, and the faces against which said rollers ride lie at right angles to each other adjacent the respective corners of said cage.
 7. In a continuous-casting machine which comprises a fixed supporting structure, a mold-support frame carried by said structure, an open-ended water-cooled mold carried by said frame, means carried by said structure for oscillating said frame and said mold vertically, and a horizontally shiftable vertically stationary guide-roll rack carried by said structure beneath said mold, the combination therewith of cooperating means on said frame and said roll rack for maintaining said roll rack in alignment with said mold as said mold moves up and down while said roll rack is stationary; said cooperating means including bearings fixed to the underside of said frame, and rollers journaled in said bearings; said roll rack including flexibly related sections and subsections, said rollers riding against the uppermost section.
 8. A conbination as defined in claim 5 in which said rack includes a pair of opposed girders and a cage carried by said girders and being rectangular in plan, and in which said mechanism includes pads carried by said girders and said cage adjacent each corner of said cage, said pads providing vertical faces which lie at right angles to each other at the respective corners against which said rollers ride. 